Outbreaks of any infectious disease at a corrections facility ought to concern everyone. The COVID-19 virus, for example, spreads readily in the overcrowded conditions, and it doesn’t stay behind bars. The staff who come into contact with inmates routinely head for home at the end of the day, and the infection risk can come with them.

This remains an issue, though thankfully the rate of infections has been on the downslope for some time, owing to the vaccine. The lingering problem at prisons? Inmates have tended to refuse to take the shot.

That word came from Lt. Gov. Josh Green, who said on Monday’s Honolulu Star-Advertiser “Spotlight Hawaii” webcast that only about one-quarter to half the inmates are vaccinated. Hawaii Community Correctional Center is the current hot spot, with 99 inmates and 13 staff testing positive this week.

There’s no required COVID-19 immunization for staff, either, and among the newest class of recruits in training as corrections officers, about half tested positive. Thirty-six of the 40 recruits opted out of the vaccine — a whopping and worrisome number.

Toni Schwartz, spokeswoman for the state Department of Public Safety, said in an emailed response to the Honolulu Star-Advertiser that the department “is looking into the legality of mandating employee vaccination.”

Most observers believe, rightly, that without a vaccine that’s fully approved by the Food and Drug Administration, a mandate does become difficult.

However, at least one — the Pfizer-BioNTech shot — is expected to gain that clearance in a few months; the University of Hawaii is counting on that to implement its vaccine requirement for student attendance on campus in the fall semester. That’s not so far away — and when the FDA flashes a thumbs-up, it should be easier to impose one, at the prisons and elsewhere.

But waiting for that eventuality means vulnerability in a risky population will persist for some time, while the state continues its slow, steady march toward a higher degree of immunity.

Schwartz also said that while the prisons department is working hard to encourage inmates to be vaccinated, the daily churn of inmates in and out makes precise tracking of vaccine status difficult.

Regardless, this status is just one more fact to add to the list of data already requiring documentation in Hawaii’s prisons and jails. From the public-health standpoint, it’s one of the most important. The need to improve on this should be self-evident.